The pricetag? US$300 million a year. It would take investing another US$800 million (plus land costs) to establish enough protected areas to preserve ecosystems currently unrepresented.

That's a chunk of change, though not much at all in the big picture of things, and making those investments may well have social benefits as well:

Conservationists say Africa is of significant importance to the world's biodiversity as it has more than 1,200 national parks, wildlife reserves and other protected areas that encompass over two million square kilometres and represent nine percent of the continent's total land area.

Millions of people, particularly the rural poor, depend for their livelihoods on these PAs, which are also a key contributor to the Gross Domestic Products of most governments. But many African governments face a daunting challenge of reconciling their development goals with sustainable management of their natural resources.

"Biodiversity has a direct link to poverty and human health in Africa as the biological resources provide food, medicine and alternative sources of income for the rural communities," Dr Hazell Shokellu said. "Thus properly established and managed protected areas can make substantial contributions to poverty reduction."